Flexible aquatic substructures

ABSTRACT

Disclosed herein are aquatic substructures capable of supporting a weight such as a wind tower and turbine. The aquatic substructures may include a central column and at least one buoyancy container connected by means of a system of cables and beams as described herein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage entry of International ApplicationNo. PCT/US19/15783 filed on Jan. 30, 2019 and claims the benefit of U.S.Provisional Application No. 62/623,805 filed on Jan. 30, 2018. Thecontents of each application listed above are incorporated herein byreference in their entirety.

CONTRACTUAL ORIGIN

The United States Government has rights in this invention under ContractNo. DE-AC36-08GO28308 between the United States Department of Energy andAlliance for Sustainable Energy, LLC, the Manager and Operator of theNational Renewable Energy Laboratory.

BACKGROUND

The offshore wind industry has struggled due to the high technical riskof the process of operating offshore wind turbines. Innovative floatingwind systems are needed to lower the levelized cost of electricity(LCOE). The LCOE is the net present value of the unit-cost ofelectricity over the lifetime of a generating structure, such as anoffshore wind turbine.

Currently utility-scale floating wind systems are based on traditionaloil and gas technology and reliability criteria that have resulted inbulky and expensive designs. The substructure and installation of anoffshore wind turbine may account for up to 40% of the total cost of theturbine. Therefore, there is ample room to lower the substructure andinstallation costs.

The foregoing examples of the related art and limitations therewith areintended to be illustrative and not exclusive. Other limitations of therelated art will become apparent to those of skill in the art upon areading of the specification and a study of the drawings.

SUMMARY

An aspect of the present disclosure is a device including a columnhaving a first end and a second end, a first container, a first beamhaving a third end and a fourth end, a first joint that connects thethird end of the first beam to the column, a second joint that connectsthe fourth end of the first beam to the first container, a first cablethat connects the second joint to the first end of the column, and asecond cable that connects the second joint to the second end of thecolumn. In some embodiments, the first joint is a universal joint, aball joint, or spherical rolling joint. In some embodiments, the secondjoint is a universal joint, a ball joint, or a spherical rolling joint.In some embodiments, the device also includes a ballast that isconnected to at least one of the column or the first container. In someembodiments, the first container is a tank containing at least one ofoxygen or nitrogen. In some embodiments, the first cable and the secondcable are fiberglass rope, metal chain links, or steel cables.

In some embodiments of the present disclosure, the container is a firstcontainer, and the device further includes a second container, a secondbeam having a fifth end and a sixth end, a third joint that connects thefifth end of the second beam to the column, a fourth joint that connectsthe sixth end of the second beam to the second container, a third cablethat connects the fourth joint to the first end of the column, and afourth cable that connects the fourth joint to the second end of thecolumn, wherein the second container and first container aresubstantially within a plane. In some embodiments, the third joint is auniversal joint, a ball joint, or spherical rolling joint. In someembodiments, the fourth joint is a universal joint, a ball joint, or aspherical rolling joint. In some embodiments, the device furthercomprises a ballast that is connected to at least one of the column, thefirst container, or the second container. In some embodiments, the firstcontainer and the second container are tanks containing at least one ofoxygen or nitrogen.

Another aspect of the present disclosure includes a method that includesconnecting a first beam to a column at a substantially right angle usinga first joint, connecting the first beam to a first container using asecond joint, and supplying compression to the first beam by connectinga first cable and a second cable to the second joint and the column,wherein the column has a first end and a second end, the first cableconnects the second joint to the first end of the column, the secondcable connects the second joint to the second end of the column, and thefirst cable and the second cable are under tension. In some embodiments,the first joint and the second joint are universal joints, ball joints,or spherical rolling joints. In some embodiments, the method furtherincludes anchoring the aquatic subsystem in place using mooring chainsattached to at least one of the column or the first container. In someembodiments, the method further includes lowering a ballast attached toat least one of the column or the first container. In some embodiments,the method further includes raising the ballast to allow the aquaticsubstructure to be moved by means of a wet tow.

Another aspect of the present disclosure is a device that includes acolumn having a first end, a second end, and a length, a buoyancycontainer, a beam having a third end and a fourth end that is at anapproximately right angle to the column, a first cable that is attachedto the second joint and the first end of the column, a second cable thatis attached to the second joint and the second end of the centralcolumn, a first joint that connects the third end of the beam to thelength of the central column, and a second joint that connects thefourth end of the beam to the buoyancy container; wherein the cables areunder tension. In some embodiments, the device further includes aballast that is connected to at least one of the column or the buoyancycontainer, a chain that connects the ballast to at least one of thecolumn or the buoyancy container, and a mooring line that connects atleast one of the column or the buoyancy container to the ocean floor. Insome embodiments, the first joint and the second joint are universaljoints, ball joints, or spherical rolling joints.

Another aspect of the present disclosure is a device that includes acolumn having a first end, a second end, and a length, a buoyancycontainer, a beam having a third end connected to the length of thecentral column and a fourth end, a first cable that connects the firstjoint to the first end of the column, a second cable that connects thefirst joint to the second end of the column, a first joint that connectsthe fourth end of the beam to the buoyancy container, and the beam isoriented at an approximately right angle to the central column; whereinthe cables are under tension. In some embodiments, the third end of thebeam is connected to the length of the central column by a second joint.In some embodiments, the first cable and the second cable comprise onelength of cable.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments are illustrated in referenced figures of thedrawings. It is intended that the embodiments and figures disclosedherein are illustrative rather than limiting.

FIG. 1 illustrates a wind tower and turbine supported by one embodimentof an aquatic substructure as described in some aspects of the presentdisclosure.

FIG. 2 illustrates another embodiment of an aquatic substructure asdescribed in some embodiments of the present disclosure.

FIG. 3 illustrates a wind tower and turbine supported by anotherembodiment of an aquatic substructure as described in some embodimentsof the present disclosure.

FIGS. 4A and 4B illustrate another embodiment of an aquatic substructureas described in some embodiments of the present disclosure.

FIG. 5 illustrates another embodiment of an aquatic substructure asdescribed in some embodiments of the present disclosure.

FIG. 6 illustrates another embodiment of an aquatic substructure asdescribed in some embodiments of the present disclosure.

FIG. 7 illustrates a column, buoyancy container, and connection systemof an aquatic substructure as described in some embodiments of thepresent disclosure.

DETAILED DESCRIPTION

In one aspect, the present disclosure describes an aquatic substructuredesigned to support a weight situated on top of a column by connectingthe column to at least two buoyancy containers using beams and cables.The cables may exert a force on each beam such that each beam may beunder tension and may be compressed. The tension of the cables andcompression of the beams allows the force of the weight to bedistributed throughout the aquatic substructure. At the distal end ofeach beam may be a buoyancy container (such as a container, cistern,tank, or combination thereof) which may be connected to the beam bymeans of a joint. The joint may allow for a reduction in the loadingforce on the beam and may allow the buoyancy container to rotate free ofthe rest of the aquatic substructure. The joint may create a moment-freeconnection between the beam and the buoyancy device.

FIG. 1 illustrates a wind tower and turbine supported by an aquaticsubstructure 100 as described in some embodiments of the presentdisclosure. As shown in FIG. 1, aquatic substructure 100 includes acolumn 105, buoyancy containers 110, a base 115, joints 125, a ballast140, lowering chain 145, and mooring lines 130. For brevity, not all ofthe buoyancy containers 110, joints 125, lowering chain 145, and mooringlines 130 are labeled in FIG. 1. In the embodiment of FIG. 1,substructure 100 supports a turbine 155 and a tower 150. In otherembodiments, substructure 100 may support various other structures oradditional towers.

In the embodiment of FIG. 1, turbine 155 may capture and convertoffshore wind to useable energy. The specifics of substructure 100 shownin FIG. 1, are based on using “material for purpose” and load reductionof its members (i.e., the beams). The embodiment shown in FIG. 1 mayrepresent an “installed” or active configuration of substructure 100,meaning the aquatic substructure is in its desired location foroperation of the turbine 155. The ballast 140 may be lowered, therebylowering the center of gravity of aquatic substructure 100, when theaquatic substructure is in its desired location for the operation of theturbine 155.

In the embodiment of FIG. 1, the buoyancy containers 110 may includemultiple tanks which are connected in three groupings to form threebuoyancy containers 110. The three groupings of tanks may be deemedthree buoyancy containers 110 for aquatic substructure 100. The tanksmay be sized as needed to support the weight of the tower 150 andturbine 155. The number of tanks in each grouping may depend on the sizeand weight of tower 150 and turbine 155. In some embodiments, a buoyancycontainer 110 may be made of up of a single tank. In other embodiments,a buoyancy container 110 may be made up of two or more tanks.

FIG. 2 illustrates another embodiment of an aquatic substructure 200, inaccordance with one or more aspects of the present disclosure. As shownin FIG. 2, substructure 200 includes a column 205, buoyancy containers210, cables 220, joint 225, beams 215 a, and base 215 b. For brevity,not all of the buoyancy containers 210, cables 220, joints 225, or beams215 a are labeled in FIG. 2. Column 205, buoyancy containers 210, base215 b, and joints 225, as shown in FIG. 2, may be substantially the sameas column 105, buoyancy containers 110, base 115, and joints 125described with respect to FIG. 1.

The configuration shown in the embodiment of FIG. 2 also includes cables220 and beams 215 a. The connection cables 220 and beams 15 a 2 mayrestrain the movement of the buoyancy containers 210 to keep thebuoyancy containers 210 from being undesirably agitated by waves orcurrent. While shown in FIG. 2 as including both base 215 b and beams215 a, the aquatic substructure 200 may, in some examples, include onlythe beams 215 a. In other words, the beams 215 a may be used in place ofthe base 215 b or in addition to the connection cables 220.

FIG. 3 illustrates a wind tower and turbine supported by anotherembodiment of an aquatic substructure as described in some embodimentsof the present disclosure FIG. 3 is a conceptual diagram illustratinganother embodiment of an aquatic substructure 300, in accordance withone or more aspects of the present disclosure. Aquatic substructure 300,as shown in FIG. 3, may be substantially similar to substructure 100 ofFIG. 1 or substructure 200 of FIG. 2. As shown in FIG. 3, aquaticsubstructure 300 includes column 305, tower 350, turbine 355, buoyancycontainers 310, joints 325, base 315, and ballast 340. Column 305, tower350, turbine 355, buoyancy containers 310, joints 325, base 315, andballast 340 may be substantially the same as column 105, tower 150,turbine 155, buoyancy containers 110, joints 125, base 115, and ballast140 described with respect to FIG. 1. The embodiment as shown in FIG. 3may represent a “transport” configuration of substructure 300. Forexample, as shown in FIG. 3, the ballast 340 may be retracted. This mayresult in substructure 300 having a lower draft (i.e., the mean waterline), which can be beneficial during wet tow, such as from a port offabrication and assembly to an install site.

One purpose of the floating wind turbine substructures depicted in theexamples of FIGS. 1-7 is to provide buoyancy and restoring force tostabilize and support the attached structure (e.g., turbine and tower),and the mass of the mooring system. The orientation and structure of theaquatic substructures as described in FIGS. 1-7 and some otherembodiments disclosed herein allow for a moment-free connection betweenthe buoyancy containers and the column, which may reduce the bendingload on the beams. This may result in a more flexible support structurefor offshore wind energy or other purposes.

The use of “material for purpose” (i.e., using lightweight components toprovide buoyancy and heavyweight components for ballast)—may allow thesubstructures to achieve stability requirements necessary for supportingthe attached structures. For instance, the substructures shown in FIGS.1-7 may limit the heel angle and tower top accelerations to within themargins defined by a wind turbine manufacturer (e.g., smaller than 10degrees and 0.3 g, or similar margins). In other words, the aquaticsubstructures as described herein may increase the stability of thesupport provided to any weight or structure they are supporting.

The buoyancy of aquatic substructures as described herein may generallybe provided by the column and the buoyancy containers. The column may bea hollow tank, container, column, or cistern, made of steel or concrete,to support the transfer of loads from the tower and turbine. Becausecolumn may be hollow, it provides some buoyancy for the substructure. Inother embodiments, the column may be dense or not hollow. The outerbuoyancy containers may be columns, containers, cisterns, or tanks madeof fiberglass or other lightweight material to provide additionalbuoyancy. The outer buoyancy containers may also be hollow or filledwith a lightweight filler such as air, nitrogen, or foam material. Thecolumn and outer buoyancy containers may be a single object or may be acollection of multiple objects together. That is, while shown in FIGS.1-7, as a single object (for the column) and multiple objects (for thebuoyancy containers), respectively, the central column and buoyancycontainers may, in various examples, each be a single object or multipleobjects. As used herein, the term column may be a container or objecthaving a circular cross section, rectangular cross section, or polygoncross section.

In FIGS. 1 and 3, the base 115 or 315 and the retractable ballast 140 or340 may be formed of concrete or other dense material, to lower thesubstructure's center of gravity. The retractable ballast may be in thesame shape as the base, or the two may be different shapes. In someembodiments the ballast may be a container filled with a dense materialsuch as water, sand, or concrete.

In some embodiments, the base 115 or 315 may be a platform or slab ofheavy concrete used at the bottom of the column 105 or 305 to lower thecenter of gravity of the substructure. It may be concrete, asphalt,fiberglass, aluminum, steel, or another solid material. In otherembodiments of the present disclosure, the function provided by the base(i.e., supporting the system and providing stability) may be provided bybeams as described herein.

To reduce the loads on the base, universal joints may be used for amoment-free connection between the base and the buoyancy containers byattaching universal joints to opposite ends of a beam connecting thecolumn to the buoyancy containers. This may allow for a more lightweightdesign. That is, since the buoyancy containers are allowed to movewithin the limitations of the universal joints, hydrodynamic wave loadsapplied on the buoyancy containers will be transferred into motion ofthe buoyancy containers rather than to the column. This may reduce theloads transferred from the buoyancy containers on to the base andcolumn, which may allow for lighter materials, as they do not need towithstand such loads. The ability of the buoyancy containers to move mayalso help to reduce the motion of the attached structure (e.g., aturbine and tower for offshore wind energy generation or anotherpurpose) by reducing the wave-induced hydrodynamic excitation of thesubstructure. This may make the aquatic substructure more stable as asupport for the attached structure.

As shown in the example of FIG. 3, the retractable ballast 340 may beretracted during transport to improve shallow water clearance (e.g., atthe port of fabrication and assembly). Raising the ballast 340 may alsoraise the center of gravity of the aquatic substructure 300, making iteasier to be relocated. The retracting may be done by pulling theballast 340 up to be in direct contact with the base 5. Once at aninstallation site, the substructure (e.g., elements 305, 310, 315, 320,and 325), and/or the structure (e.g., the tower 350 and turbine 355) maybe connected to a catenary mooring system (e.g., elements 130 and 145shown in FIG. 1). Furthermore, the retractable ballast 340 may belowered via the ballast lowering chain 145 to further lower the centerof mass for operational stability when the aquatic substructure hasreached the desired installation location.

In some examples, the mooring system may be pre-installed. The mooringsystem may include mooring chains 130 and anchors 160. The anchors 160may be of a drag embedment type, a suction pile type, or other suitabletype. The anchors 160 may attach the aquatic substructure 100 to the seafloor, a mooring device (such as a dock or permanent anchor), or anotheraquatic substructure. In some examples, the mooring system may be easilydetachable, allowing a wet tow of the substructure, and aquaticstructure back to port for maintenance and/or end of lifecycledismantling or repurposing of the unit.

The embodiment as shown in FIG. 2 depicts two optional components forconnecting the outer buoyancy containers 210 to one another and/or tothe column 205. In the example of FIG. 2, connection cables 220 and/orbeams 215 may be used to restrain the outer buoyancy containers 210,thereby preventing excessive movement (e.g., in rough waters). Thecables could be steel wire rope, composite fiber rope, chains, or othersuitable material. The cables may be under tension.

FIGS. 4A and 4B illustrate another embodiment of an aquatic substructureas described in some embodiments of the present disclosure. In theexamples of FIGS. 4A and 4B, substructure 400 may be configured tosupport a wind turbine to capture and convert offshore wind to useableenergy. Substructure 400 may include mooring chains 430, upper supportcables 420 a, lower support cables 420 b, beams 415, a column 405, andbuoyancy containers 410. For brevity, not all of the upper supportcables 420 a, the lower support cables 420 b, the beams 415, or thebuoyancy containers 410 are labelled in FIGS. 4A and 4B. Substructure400 are shown in the examples of FIGS. 4A and 4B with a connectedmooring system (e.g., mooring lines 430). In FIG. 4A, the dots representjoints 425, which may be located on either end of each of the beams 415.The joints may be universal joints, or any joint which allows for amoment free connection. Again, for brevity, not all universal joints arehighlighted with dots in FIGS. 4A and 4B, but such additional universaljoints may be discerned through symmetry of substructure 400.

One of the aspects that sets substructure 400 apart from related artsubstructures is its utilization of cables, universal joints, and radialbeams, resulting in a light weight, load path optimized design. That is,while some floating structures may use large beams that guide buoyancy-and gravity-related loads through the substructure, the design depictedin FIGS. 4A and 4B avoid the costly transfer of loads through bendingmoments. Instead, as shown in FIGS. 4A and 4B, the internal loads may berouted through a combination of cables (e.g., wire rope, composite fiberropes, chains, or other suitable means) and beams to obviatecost-intensive and heavy bending-resisting beam. The combination ofcables, universal joints, and beams also introduces additionalcompliance/flexibility to the substructure, which means some of thewave-induced loads applied to the substructure may cause motion of thesubstructure members within the limitations of the universal joints.This may help to reduce the wave-induced motion of attached structures(e.g. wind turbines, etc.). The beams may also be compressive members.

The cables being under tension may place a force on the beam which maycause it to be compressed or to bear a load. The joint at the distal endof the beam may allow

In some embodiments, the column may be located at the bottom of thetower. The column may central to the buoyancy containers or may be inanother orientation. The column may be comprised of a solid materialsuch as concrete, fiberglass, plastic, steel, aluminum, or anothermetal. In some embodiments, the column may be hollow. The column may beused to support the transfer of the loads for a tower and turbine, ifpresent. In some embodiments, the column may be the center around whichthe buoyancy containers are oriented. In other embodiments, the columnmay be in line (i.e., substantially within a plane) with one or morebuoyancy containers. In some embodiments, there may be multiple columnseither positioned together or arranged in a triangular or polygonalshape.

In some embodiments, the buoyancy containers may be used to create mostof the needed buoyancy by the aquatic substructure. The buoyancycontainers may be tanks, cans, cisterns, or containers made offiberglass, plastic, or another solid material. The buoyancy containersmay be substantially cylindrical, spherical, canonical, or rectangular.The buoyancy containers may have a smaller radius at one end of thecontainer than at the other; that is, the buoyancy containers may becone- or pyramid-shaped. The buoyancy containers may be filled with air,oxygen, nitrogen, or other inert gases. The buoyancy containers may befilled with foam or other lightweight materials. In some embodiments,the buoyancy containers may not be a hollow tank or reservoir, but maybe a solid, flexible, and lightweight material. The buoyancy containersmay be any material which floats on water.

The number of buoyancy containers used in an aquatic substructure maydepend on the size of the column, weight of the tower (or other objectbeing supported), and/or the wave conditions at the site of use. Whencircumstances require more buoyancy or a larger support structure, thenumber of buoyancy containers may be 3, 5, 10, or any other number ofbuoyancy containers. As used herein, the term “buoyancy container” maybe comprised of multiple tanks or containers attached to each otherusing rope, metal wiring, chains, or other methods.

In some embodiments, the joints may be points throughout thesubstructure where there is a moment-free connection for a lightweightdesign. These joints may allow the substructure to be flexible as thesubstructure is jostled in waves. The joints may be universal joints,ball joints, pin joint, U joints, or other types of joints which allowfor a moment-free connection of the base or beams to the buoyancycontainers. In some examples, certain joints may be of one type whileother joints may be of another type. The type of joint may be based onthe desired motility of the joint.

In some embodiments, the joints may allow the buoyancy containers torotate and move independent of the rest of the structure. The joints mayreduce the bending load on the beams or the base by the weight of thecolumn and tower. In some embodiments, there may be joints connectingthe buoyancy containers to the base or to connect the buoyancycontainers to beams. In some embodiments, there may be joints on eitherends of beams (i.e., one joint connecting the beam to the column and asecond joint connecting the beam to the buoyancy container).

In some embodiments, the ballast may be a concrete slab deployed usingcables or chains at the installation site to lower the platform centerof gravity for stability and improved performance. In some embodiments,the ballast may be a structure similar to the base or orientation of thebuoyancy containers (i.e., a flat and relatively thin piece of concreteor other dense material). In other embodiments the ballast may be alarge tank or container for holding water or another dense substance,with the ability to allow the dense substance to enter and exit theballast. The ballast may be substantially rectangular or may be apolygon in the same shape as the base. In other embodiments, the ballastmay be cylindrical, spherical, or cubic. In some embodiments there maybe multiple ballasts connected to the column and/or the buoyancycontainers.

In some embodiments, the ballast lowering chain may be a cable to lowerthe retractable ballast. The lowering chain may be made of metal,fiberglass, plastic, concrete, or a mixture of materials. The chain mayhave links which connect to form the chain or may be a continuous line.The ballast lowering chain may be connected to one or more of the columnor a buoyancy container.

In some embodiments, the mooring chain may be an easily detachablesystem which allows for a wet tow of the substructure. A wet tow ofsubstructure may be done to reposition the substructure, to return thesubstructure to quayside for maintenance or end-of-lifecycle dismantlingor repurposing of the substructure. The mooring chain may attach to ananchor when the aquatic substructure is in position for use or forstorage.

In some embodiments, an anchor may be used to attach the aquaticsubstructure to the sea floor. The anchor may be a drag embedment, pipeanchors, or may be any device capable of securing the aquaticsubstructure to the sea floor. The anchor and mooring chain system maybe any device, or combination of devices, which allows the aquaticsubstructure to be held in place.

In some embodiments, the base may be replaced by a system of beams andcables. In other embodiments, the base may be used in addition to beamsand cables. The beams and cables may allow for the aquatic substructureto be assembled at its site of use and may result in a decrease inconstruction costs. Additionally, the beams and cables may be easilyreplaced in a piecemeal fashion as they corrode, age, or aredeteriorated by weather, salt water, and the elements. In someembodiments the cables may be under tension. The cables may connect ajoint at the distal end of a beam (i.e., the end of a beam away from thecolumn) to the column. The cables may connect the joint to the columnwith connection points at both the top end and lower end of the column.In some embodiments the lower connection of the cables may be underneaththe mean water line. As previously stated, the cables may be replaced ina piecemeal fashion as needed which may reduce maintenance costs.

In some embodiments, the mooring chains, upper support cables, and lowersupport cables may be made of metal chain, fiber rope, plastic, oranother connecting material. The mooring chains, upper support cables,and lower support cables, may be made with different materials or mayall be made with the same materials. The upper support cables mayconnect the buoyancy containers with the top of the column. The lowersupport cables may connect the buoyancy containers with the bottom ofthe column. There may be a single upper support cable per buoyancycontainer or there may be multiple. There may be a single lower supportcable per buoyancy container or there may be multiple. In embodimentswhere there are multiple upper or lower support cables per buoyancycontainer the cable may be wrapped around the column (i.e., the multipleupper or lower support cables may be made of a single connected cable).Cables may be attached to the column by means of a shackle, a ring, oranother securing mechanism embedded or welded to the column. Each cablemay have a turnbuckle, stretching screw, or bottle screw to adjust thetension and length of the cable.

In some embodiments, the buoyancy containers may be made of acombination of multiple tanks or may be a single container at eachlocation. The containers may be substantially hollow or may be filledwith a gas or a lightweight material. The gas may be substantiallyoxygen, nitrogen, helium, or any combination thereof. The gas may beinert. The lightweight material may be foam, cork, or pellets. In someembodiments the buoyancy containers may be a sold material that islightweight, such as cork or polyethylene foam. The buoyancy containersmay be made with fiberglass, steel, aluminum, plastic, or another solidmaterial. The number of buoyancy containers required for the aquaticsubstructure may be scaled based on the size of the column and/or theweight being supported by the column. For example, a large column mayrequire five or six buoyancy containers, while a small column may onlyrequire two buoyancy containers.

In some embodiments, a beam may be connected to a buoyancy container andthe column. Each buoyancy container may be connected to a solid lengthbeam. The beams may be a rigid shaft, rod, pipe, or solid material suchas concrete, steel, aluminum, plastic, fiberglass, or somethingsubstantially similar. The beams may be compressed by the force of thecables connecting the buoyancy containers to the column. A beam may beattached to a buoyancy container and column using a universal joint, asindicated by a dot in the figure. In some embodiments, the beams may becomprised of several smaller beams connected to make a supportstructure. The orientation of the cables connecting the outer joint(i.e., the joint at the distal end of the beam) to the column may resultin the beam carrying the bending load of the aquatic sub structure.

In some embodiments, each beam may have a joint at both terminal ends ofits length. The joints may be a universal joint, ball joints, or anotherjoint which relieves moment transfer, or any combination thereof (i.e.,the two joints need not be the same type of joint). The joints may allow360° rotation in the x-y plane. The joints may allow the buoyancycontainers to rotate and to relieve the bending loads on the beam. Thejoints may allow for a moment free connection between the buoyancycontainers and the beams.

In some embodiments, each beam may have a joint only at the terminal endopposite from the column (i.e., the distal end). That is, in someembodiments, the beam may be connected to the buoyancy container bymeans of a joint and may be connected to the column by anotherconnection mechanism such as welding.

In some embodiments, the substructure may have a ballast. The ballastmay be a solid block or a hollow container capable of retaining water oranother dense material. The ballast may be made of concrete, asphalt, ormay be made of a plastic, steel, aluminum, or fiberglass shell which maybe filled with water. The ballast may be lowered using a ballastlowering chain. The ballast lowering chain may be a metal chain, fiberrope, plastic cable, or another other connecting device. The ballast maybe raised to allow the structure to be moved or may be lowered tostabilize the substructure. When the ballast is lowered the substructuremay have a lower center of gravity and may remain substantially upright.

In some embodiments, the mooring chains may attach the substructuredirectly to the sea floor. In other embodiments, the mooring chains mayattach the substructure to a moor, dock, or other substructures. In someembodiments, the mooring chains may be made of substantiality similarmaterial to the support cables. In other embodiments, the mooring chainsmay be made of a different material from the support cables. The mooringchains may be made of metal chain links, fiber, or other rope-likematerials.

FIG. 5 illustrates another embodiment of an aquatic substructure asdescribed in some embodiments of the present disclosure. In someembodiments, as shown in FIG. 5, the aquatic substructure 500 mayinclude a column, 505, buoyancy containers 510, beams 515, upper cables520 a, lower cables 520 b, and mooring chains 530. As shown in theexample of FIG. 5, the column 505 may not be centered between thebuoyancy containers 510 but the aquatic substructure 500 may be in aV-shape with the column 505 connecting two buoyancy containers 510. Theangle between the two buoyancy containers 510 may be less than 90°. Insome embodiments, the angle between the two buoyancy containers may begreater than 90°. In this embodiment, cables 520 may connect a joint(not shown in this figure) to the column 505. The joint may be locatedat the distal end of the beam (i.e., the terminal end of the beamfarthest from the column). The buoyancy containers 510 may be connectedto the joints. In some embodiments, the beams 515 may be connected tothe column 505 by means of a shackle, ring, or another device which maybe embedded or welded to the column (not shown).

FIG. 6 illustrates another embodiment of an aquatic substructure asdescribed in some embodiments of the present disclosure. The aquaticsubstructure 600, as shown in FIG. 6 may include a column 605, buoyancycontainers 610, beams 615, upper cables 620 a, lower cables 620 b,mooring chains 630, ballast lowering chains 645, and a ballast 640. Insome embodiments, as shown in FIG. 6, the aquatic substructure 600, mayhave a column 605, which may be attached to three buoyancy containers610. Mooring lines 630 may connect the buoyancy containers 610 andcolumn 605 to the ocean floor, an anchor, or another aquaticsubstructure. Each buoyancy container 610 may be connected to a singlemooring line 630, or multiple mooring lines 630 may be connected to eachbuoyancy container 610. Additionally, the aquatic substructure 600 mayhave a single mooring line connecting either the column 605 or a singlebuoyancy container 610 to something to the ocean floor, an anchor, amoor, or another aquatic substructure.

As shown in FIG. 6, the column 605 may be connected to the buoyancycontainer 610 by a system of cables and beams. The connection mechanismof the joints connected to the beams and columns are shown in moredetail in FIG. 7. The support cables 620 may connect the joint at thedistal end of the beam (i.e., the end of the beam closest to thebuoyancy container and farthest from the column) to the column. Thecables may connect with both ends of the column, or a single end. Thatis, the upper cables 620 a may connect with the upper end of the column605 and the lower cables 620 b may connect with the lower end of thecolumn 605 or only one type of cable may connect to one end of thecolumn 605. For the upper support cables there may be two cablesconnecting the joint at the distal end of the beam to the column, orthere may be a single cable which wraps around the column then returnsto the joint at the distal end of the beam. For the lower support cablesthere may be two cables connecting the joint at the distal end of thebeam to the column, or there may be a single cable which wraps aroundthe column then returns to the join at the distal end of the column. Thecables may connect to the joint and the central column using a shackle,a ring, or a device embedded or welded to the joint and/or centralcolumn. The cables may each contain a turnbuckle to allow the cables tobe tightened or loosened as needed. The upper support cables 620 a mayconnect the buoyancy containers 610 to the top or upper end of thecolumn. The lower support cables 620 b may connect the buoyancycontainers 610 to the bottom or lower end of the column. Someembodiments may have either upper support cables 620 a or lower supportcables 620 b only, although both is preferred.

FIG. 7 illustrates a column, buoyancy container, and connection systemof an aquatic substructure as described in some embodiments of thepresent disclosure. The connection system of an aquatic substructure 700as shown in FIG. 7 includes a column 705, cables 720, joints 725, a beam715, and a buoyancy container 710. FIG. 7 shows how the buoyancycontainers may be connected to the column in some embodiments. As shownin FIG. 7, the beam 715 may be compressed by the tension of cables 720.The cables 720 may attach to the joint 725 at the end of beam 715 andprovide such a force as to compress the beam 715. Joint 725 may allowbuoyancy container 710 to move independently. Joints 725 may be auniversal joint, ball joint, pin joint, or other joint which allowsbuoyancy container 710 to move independently of the beam 715. Thetension of the cables 720 may keep the beam 715 compressed, while therange of motion allowed by the joint 725 may allow the buoyancycontainers 710 to move and rotate independently of the rest of theaquatic substructure. As shown herein, the column 705, beam 715, joints725, cables 725, and buoyancy container 710 may be substantially thesame as column 605, beams 615, joints 625, and buoyancy containers 610as described with respect to FIG. 6.

The foregoing disclosure includes various examples set forth merely asillustration. The disclosed examples are not intended to be limiting.Modifications incorporating the spirit and substance of the describedexamples may occur to persons skilled in the art. These and otherexamples are within the scope of this disclosure and the followingclaims.

What is claimed is:
 1. A device comprising: a column having a first endand a second end; a first container; a first beam having a third end anda fourth end; a first joint that connects the third end of the firstbeam to the column; a second joint that connects the fourth end of thefirst beam to the first container; a first cable that connects thesecond joint to the first end of the column; and a second cable thatconnects the second joint to the second end of the column.
 2. The deviceof claim 1, wherein the first joint is a universal joint, a ball joint,or spherical rolling joint.
 3. The device of claim 1, wherein the secondjoint is a universal joint, a ball joint, or a spherical rolling joint.4. The device of claim 1, further comprising a ballast that is connectedto at least one of the column or the first container.
 5. The device ofclaim 1, wherein the first container is a tank containing at least oneof oxygen or nitrogen.
 6. The device of claim 1, wherein the first cableand the second cable are fiberglass rope, metal chain links, or steelcables.
 7. The device of claim 1, wherein the container is a firstcontainer, further comprising: a second container that is substantiallywithin a plane with the first container; a second beam having a fifthend and a sixth end; a third joint that connects the fifth end of thesecond beam to the column; a fourth joint that connects the sixth end ofthe second beam to the second container; a third cable that connects thefourth joint to the first end of the column; and a fourth cable thatconnects the fourth joint to the second end of the column.
 8. The deviceof claim 7 wherein the third joint is a universal joint, a ball joint,or spherical rolling joint.
 9. The device of claim 7, wherein the fourthjoint is a universal joint, a ball joint, or a spherical rolling joint.10. The device of claim 7, further comprising a ballast that isconnected to at least one of the column, the first container, or thesecond container.
 11. The device of claim 7 wherein the first containerand the second container are tanks containing at least one of oxygen ornitrogen.
 12. A method of constructing an aquatic substructurecomprising: connecting a first beam to a column at a substantially rightangle using a first joint; connecting the first beam to a firstcontainer using a second joint; and supplying compression to the firstbeam by connecting a first cable and a second cable to the second jointand the column, wherein: the column has a first end and a second end,the first cable connects the second joint to the first end of thecolumn, the second cable connects the second joint to the second end ofthe column, and the first cable and the second cable are under tension.13. The method of claim 12, wherein the first joint and the second jointare universal joints, ball joints, or spherical rolling joints.
 14. Themethod of claim 12 further comprising anchoring the aquatic substructurein place using mooring chains attached to at least one of the column orthe first container.
 15. The method of claim 12 further comprisinglowering a ballast attached to at least one of the column or the firstcontainer.
 16. The method of claim 12 further comprising raising aballast attached to at least one of the column or the first container toallow the aquatic substructure to be moved by means of a wet tow.
 17. Adevice comprising: a column having a first end, a second end, and alength; a buoyancy container; a beam having a third end and a fourth endthat is at an approximately right angle to the column; a first cablethat is attached to the second joint and the first end of the column andunder tension; a second cable that is attached to the second joint andthe second end of the central column and under tension; a first jointthat connects the third end of the beam to the length of the centralcolumn; and a second joint that connects the fourth end of the beam tothe buoyancy container.
 18. The aquatic substructure device of claim 17further comprising: a ballast that is connected to at least one of thecolumn or the buoyancy container; a chain that connects the ballast toat least one of the column or the buoyancy container; and a mooring linethat connects at least one of the column or the buoyancy container tothe ocean floor.
 19. The aquatic substructure device of claim 17,wherein the first joint and the second joint are universal joints, balljoints, or spherical rolling joints.
 20. A device comprising: a columnhaving a first end, a second end, and a length; a beam having a thirdend connected to the length of the central column and a fourth end; abuoyancy container connected to the fourth end of the beam by a firstjoint; a first cable that connects the first joint to the first end ofthe column and is under tension; a second cable that connects the firstjoint to the second end of the column and is under tension; and the beamis oriented at an approximately right angle to the central column. 21.The aquatic substructure of claim 20, wherein the third end of the beamis connected to the length of the central column by a second joint. 22.The aquatic substructure of claim 17, wherein the first cable and thesecond cable comprise one length of cable.